1. Field of the Invention
The present invention relates to night vision devices. More particularly, the present invention relates to a night vision device which includes a separable modular assembly including an image intensifier tube and a high-voltage power supply circuit for the intensifier tube. The separable modular assembly provides high-voltage connection between the power supply and the image intensifier tube, and also physically connects these modular components separably while providing shielding, sealing, and environmental protection to high-voltage electrical connector features of the modules.
2. Related Technology
A conventional night vision device is known as the AN/PVS-7B. This night vision device includes a housing with a single objective lens through which is received low-level light from a scene too dark to be viewed with the unaided eye. The housing of the conventional AN/PVS-7B also included an image intensifier tube which provides an image in phosphor yellow/green light representative of the low-level scene. An image splitter and a pair of eye pieces allow the user of the device to view the intensified image with each eye.
The conventional AN/PVS-7B also includes a battery providing electrical power to the device, and a high-voltage power supply circuit which converts the comparatively low voltage power from the battery to high-voltage levels appropriate for operation of the image intensifier tube.
Conventionally, the image intensifier tube and power supply of night vision devices are combined and are encapsulated into a single module by the use of potting compound. Generally, this module is referred to as the image intensifier module, or IIM. This current technology for making night vision devices involves a multi-stage, labor intensive manufacturing process. As a first step in the conventional manufacturing process for an IIM, the electrical contacts at tabs and flanges of the image intensifier tube are soldered to leads from the high-voltage power supply. Next, the image intensifier tube is given a conformal coating of RTV, or room-temperature-vulcanizing silicone potting compound. As so connected, the image intensifier tube and power supply are inserted into a housing which is held within a mold. The housing is filled with a potting compound. Next, a back plate is placed on the assembly, and is sealed into place using additional RTV compound.
With the conventional IIM, if subsequent testing reveals a defect in either the image intensifier tube, or in the high-voltage power supply circuit; or if, for example, something as simple as one of the electrical connections between these components having a defect, such as a cold solder joint, then the encapsulated IIM module must be destructively taken apart before access to the components can be achieved. Of course, irreparable damage to the power supply or to the image intensifier tube, or to both, is very likely to result from such destructive disassembly of the IIM. However, the only alternative is to throw away defective IIM modules with their expensive power supplies, and very expensive image intensifier tubes. Such disposal of component parts which may have only a minor and easily repairable defect is a great waste incident from the conventional technology for making IIM's.